By way of background concerning some conventional systems, it is noted that computing devices have traditionally stored information and associated applications. To these ends, implementing an efficient memory management scheme is desirable for achieving increased computing performance. Developments in automatic memory management schemes have been particularly desirable over manual memory management schemes. Garbage collector algorithms, for instance, are automatic memory management schemes which attempt to reclaim memory occupied by objects that are no longer in use by a particular program.
Tracing garbage collectors are the most common type of garbage collector. Tracing garbage collectors first determine which objects are reachable (or potentially reachable), and then discard all remaining objects. A reachable object can be defined as an object for which there exists some variable in the program environment that led to the variable, either directly or through reference from other reachable objects. More precisely, objects are generally reachable in two ways. First, a distinguished set of objects, known as roots, are assumed to be reachable. Typically, these include the objects referenced from anywhere in the call stack (that is, all local variables and parameters in the functions currently being invoked), and any global variables. Second, anything referenced from a reachable object is itself deemed reachable.
A complication with conventional garbage collectors, in languages with both reference types and unboxed value types, is that the garbage collectors distinguish which variables on a call stack are regular values (e.g., integers) and which are references (e.g., pointers). Such distinction would be useful in such systems for distinction purposes since an integer and a reference might otherwise look alike as represented in memory. In this regard, the garbage collector would be able to use the distinction to decide whether to treat a particular element as a reference and follow the reference, or whether it is simply a primitive value.
The above-described deficiencies of today's memory management schemes are merely intended to provide an overview of some of the problems of conventional systems, and are not intended to be exhaustive. Other problems with the state of the art and corresponding benefits of some of the various non-limiting embodiments may become further apparent upon review of the following detailed description.